Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
12 ratings

Wednesday - March 17, 2010

From: Little Chute, WI
Region: Midwest
Topic: Shrubs
Title: Native trees or shrubs for containers on roof in Wisconsin
Answered by: Nan Hampton

QUESTION:

Looking for native trees/shrubs to be planted in containers on a flat roof w/south-southeast exposure. Gets pretty warm in the summer and pretty cold in the winter. How big would the container have to be?

ANSWER:

First, let me refer you to our article, Container Gardening with Native Plants.  You will see in the article that the recommendation for the size of the pot is: 

"Select a container that will accommodate the full sizes of the plants it will house. It should provide ample root space and have a substantial base to offset top-heaviness (both visually and in terms of stability)."

Winter weather in Wisconsin, however, presents an addtional consideration for the size of the pot you can use.  I believe you can handle the summer heat as long as you pick plants that are happy growing in full sun and you give them adequate water.  However, the winters are another matter.  Roots in a container will not have the same protection from freezing that roots buried in the ground will have.  With container plants you will need to move them to a protected environment to protect their roots as the winter temperatures drop well below freezing.  Consequently, you will need to select plants that fit into containers that you will be able to move to a protected place. You can read advice on preparing container plants for winter weather in the article, Maintaining Winter Gardens in Gladwin, MI, from the National Gardening Association.

Below are shrubs that are Wisconsin natives that grow in full sun.  If the your area is in shade (less than 2 hours sun per day) or part shade (2 to 6 hours of sun per day), you can find recommendations for other plants in our Wisconsin Recommended list.  You can use the NARROW YOUR SEARCH option to limit the list to only 'Shrubs' by choosing that selection under GENERAL APPEARANCE.

Actaea rubra (red baneberry)

Amorpha fruticosa (desert false indigo)

Cornus racemosa (gray dogwood)

Dasiphora fruticosa ssp. floribunda (shrubby cinquefoil)

Physocarpus opulifolius (common ninebark)

Symphoricarpos albus (common snowberry)

Shepherdia canadensis (russet buffaloberry)

Yucca filamentosa (Adam's needle) and here is more information.

Here are photos of the above plants from our Image Gallery:


Actaea rubra

Amorpha fruticosa

Cornus racemosa

Dasiphora fruticosa ssp. floribunda

Physocarpus opulifolius

Symphoricarpos albus

Shepherdia canadensis

Yucca filamentosa

 


 

 

More Shrubs Questions

Are Texas Sage plants being harmed by nearby Rosemary.
June 08, 2015 - For 6+ years I've been growing Rosemary shrubs interspersed with Texas Sage. For the past two years the Texas Sage has been looking sickly and have not produced any flowers and the Rosemary is becom...
view the full question and answer

How to prune a Lantana tree
October 02, 2015 - I have a potted Lantana tree that will come indoors for the winter. It is quite large and should I prune it back for the winter? If yes, how do I prune it?
view the full question and answer

Identification of shrub in Florida
July 03, 2008 - Hello Mr. Smarty Plants, I have a question about identifying some bushes. The bushes I have seen through areas of Florida and they seem to be used most often as natural fences. These are the charac...
view the full question and answer

Native trees or shrubs for privacy in Tonkawa, OK
April 30, 2009 - I live in North Central Oklahoma and I want to plant trees or shrubs along 100 ft of creek to create privacy. I would like them to grow at least 15 to 20 ft tall. What would you recommend for this l...
view the full question and answer

Shrubs for a fenceline in NY
June 16, 2011 - Need to replace shrubs along a fence. Currently have Honeysuckle and they are very old. Would like to have something different with more color & interest during winter months. The line of shrubs are h...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.